Various devices are known for assisting an invalid into and from a seated position. For example, Hunter in U.S. Pat. No. 3,925,833 describes a hoist assembly designed to be positioned over a toilet. The hoist provided only for vertical movement of the toilet seat. For many invalids, however, vertical movement alone of the seat which remains in a horizontal attitude is insufficient assistance in achieving a seated position. In moving from an upright position into a seated position, an individual must slide onto the vertically elevated, horizontal seat. This requires the knees to be bent to engage the seat with the buttocks and/or a modicum of strength in the upper and lower body in order to slide onto the seat, either in the elevated position or as the seat is being vertically lowered. Moving from a seated position into a standing position is likewise difficult since the individual must have sufficient body strength to push the buttocks from the rear of the seat to the front of the seat.
Other invalid assisting devices pivot the rear of the seat upwardly about an axis at the front of the seat. Burke in U.S. Pat. No. 3,479,087, for example, describes a toilet seat pivotally hinged at the front thereof. This type of device may be useful for a limited number of people depending upon the individual's height and the height of the particular toilet in conjunction with which it is used. However, for relatively tall individuals, such a device may not provide sufficient vertical elevation so that the seat does not provide for sufficient vertical extension of the legs when assuming a seated or standing position therewith. Conversely, when such a device is used with a relatively short individual it may not allow proper placement of the buttocks towards the rear of the seat with the result that the relatively short individual may still be required to use sufficient body strength to horizontally reposition the body once the horizontal position is assumed, i.e. a relatively short individual will end up with the buttocks being positioned towards the front of the seat and must slide the buttocks towards the rear of the seat once the seat has assumed a horizontal position for comfortable seating.
One device described by Epstein in U.S. Pat. No. 4,031,576 simultaneously vertically moves and pivots the seat between standing and seated positions. The rear of the seat is hingedly connected to a support which may be vertically elevated. The front of the seat is hinged to one end of a brace. The other end of the brace is hinged to a support generally in the same vertical plane as the hinge on the rearmost portion of the seat. This seat is elevated and pivoted simultaneously by vertically elevating the rear hinge of the seat. However, since the rear hinge generally remains in the same plane as the end of the brace attached to the frame, pivoting of the seat in this manner obtains a rearward movement of the front of the seat as the rear of the seat is elevated vertically. When using the device to assume a seated position over a toilet, for example, the individual must straddle the toilet with one leg on either side thereof in order to engage the vertically elevated, downwardly pivoted seat with the buttocks. Alternatively, with the feet in front of the toilet, the individual would have to lean and tend to fall backwards to engage the seat with the buttocks. If the initial straddling position is used, then, when the seated position is assumed the feet and calves must, in addition, be moved forward of the toilet from the sides thereof to obtain a comfortable seated position. Similarly, when assuming a standing position from the seated position, one must be careful to place the feet in a straddling position over the toilet before elevating the seat assembly, or else the individual will have to lean backwards against the seat as it is raised with the feet in front of the toilet and push one's body forward to disengage the toilet seat.
Another device described by Cool in U.S. Pat. No. 3,473,174 has a pivot point forward of the foremost end of the seat. Thus, in this device the elevation of the seat results in the forward movement of the seat with respect to the toilet bowl. In addition, the Cool device has several disadvantages such as, for example, that it requires replacement of the conventional seat with the seat attaohed to the assisting device, that the assisting device must be securely attached to the toilet and this requires an installation step, and that the support of the seat in the elevated position uses the toilet for structural stability. Moreover, since the vertical elevation of the seat is simultaneous with the pivoting, an invalid may slide off the seat prematurely during the pivoting process.